This invention relates generally to pen-based computing systems, and more particularly to recording audio in a pen-based computing system.
When trying to absorb a large amount of information delivered orally and possibly visually, such as in a business meeting or classroom setting, people commonly use a pen to take notes on paper. However, once disembodied from the oral presentation in which they were taken, even good notes lose much of their meaning because the context for the notes has been lost. For this reason, people often record a presentation as well as take notes. Since people commonly use a pen to take the notes, it is convenient to incorporate a microphone into the pen. In smart pen computing system, for example, a microphone may be embedded into the smart pen to record audio data while the user takes notes.
However, conventional recording devices have several significant drawbacks. First, use of the smart pen will generate noise very close to a microphone that is embedded in the pen. Handwriting and tapping the pen are common types of input gestures for a smart pen. Handwriting creates noise as the smart pen travels across the paper. This is the case even if the smart pen is not leaving ink—for example, a non-marking stylus traveling across a touch screen. Tapping the pen obviously creates noise as the pen tip impacts the writing surface. With a microphone located in the pen itself, these types of noise can be significant during audio recording since they are so close to the microphone.
In addition, mobile audio recording devices typically use a single microphone that has not been tuned to the physical environments where the recording takes place. Additionally, these microphones typically are used to record a single audio source (e.g., classroom lecturer) but often in a setting where there may be multiple other audio sources (e.g., fellow classmates in the lecture). Small audio recording devices, such as those embedded into a pen, typically lack acceptable far field recording capabilities. In addition, recording devices with a single microphone, or with conventional configurations of two microphones intended for stereo recordings, capture audio without differentiation, or with very little differentiation, as to the directional source of the audio. When two or more speakers or sound sources are recorded that are perceived by the listener as being similar in nature, the listener is often unable to differentiate between the speakers or sound sources. As a result, in an environment where there are multiple sources of audio (e.g., a meeting room with several people, or a classroom where the lecturer and fellow classmates are speaking simultaneously) or where the desired source is at some distance from the recording device, it can be difficult to identify the desired source when the recorded audio is replayed.
Accordingly, new approaches to recording audio are needed to fill the needs unmet by existing methods.